/* Emulate the Toshiba 1000 plasma display. This display has a fixed 640x200
 * resolution. */
#include <stdlib.h>
#include "ibm.h"
#include "device.h"
#include "io.h"
#include "mem.h"
#include "timer.h"
#include "video.h"
#include "vid_cga.h"
#include "vid_t1000.h"

#define T1000_XSIZE 640
#define T1000_YSIZE 200

/*Very rough estimate*/
#define VID_CLOCK (double)(651 * 216 * 60)

#define T1000_OUTPUT_DISPLAY_INTERNAL 1u
#define T1000_OUTPUT_DISPLAY_EXTERNAL 0u
#define T1000_OUTPUT_DISPLAY_UNSET 255u
/* Mapping of attributes to colours */
static uint32_t blue, grey;
static uint8_t boldcols[256]; /* Which attributes use the bold font */
static uint32_t blinkcols[256][2];
static uint32_t normcols[256][2];
static uint8_t language;

/* Video options set by the motherboard; they will be picked up by the card
 * on the next poll.
 *
 * Bit  1:   Danish
 * Bit  0:   Thin font
 */
static uint8_t st_video_options;
static uint8_t st_enabled = 1;
static uint8_t st_display_internal = T1000_OUTPUT_DISPLAY_UNSET;

void t1000_video_options_set(uint8_t options) {
        st_video_options = options & 1;
        st_video_options |= language;
}

void t1000_video_enable(uint8_t enabled) { st_enabled = enabled; }

void t1000_display_set(uint8_t internal) { st_display_internal = internal; }

uint8_t t1000_display_get() { return st_display_internal; }

typedef struct t1000_t {
        mem_mapping_t mapping;

        cga_t cga; /* The CGA is used for the external
                    * display; most of its registers are
                    * ignored by the plasma display. */

        int font;        /* Current font, 0-3 */
        int enabled;     /* Hardware enabled, 0 or 1 */
        int internal;    /* Using internal display? */
        uint8_t attrmap; /* Attribute mapping register */

        uint64_t dispontime, dispofftime;

        int linepos, displine;
        int vc;
        int dispon;
        int vsynctime;
        uint8_t video_options;

        uint8_t *vram;
} t1000_t;

static void t1000_recalctimings(t1000_t *t1000);
static void t1000_write(uint32_t addr, uint8_t val, void *p);
static uint8_t t1000_read(uint32_t addr, void *p);
static void t1000_recalcattrs(t1000_t *t1000);

static void t1000_out(uint16_t addr, uint8_t val, void *p) {
        t1000_t *t1000 = (t1000_t *)p;
        switch (addr) {
                /* Emulated CRTC, register select */
        case 0x3d0:
        case 0x3d2:
        case 0x3d4:
        case 0x3d6:
                cga_out(addr, val, &t1000->cga);
                break;

                /* Emulated CRTC, value */
        case 0x3d1:
        case 0x3d3:
        case 0x3d5:
        case 0x3d7:
                /* Register 0x12 controls the attribute mappings for the
                 * LCD screen. */
                if (t1000->cga.crtcreg == 0x12) {
                        t1000->attrmap = val;
                        t1000_recalcattrs(t1000);
                        return;
                }
                cga_out(addr, val, &t1000->cga);

                t1000_recalctimings(t1000);
                return;

                /* CGA control register */
        case 0x3D8:
                cga_out(addr, val, &t1000->cga);
                return;
                /* CGA colour register */
        case 0x3D9:
                cga_out(addr, val, &t1000->cga);
                return;
        }
}

static uint8_t t1000_in(uint16_t addr, void *p) {
        t1000_t *t1000 = (t1000_t *)p;
        uint8_t val;

        switch (addr) {
        case 0x3d1:
        case 0x3d3:
        case 0x3d5:
        case 0x3d7:
                if (t1000->cga.crtcreg == 0x12) {
                        val = t1000->attrmap & 0x0F;
                        if (t1000->internal)
                                val |= 0x20; /* LCD / CRT */
                        return val;
                }
        }

        return cga_in(addr, &t1000->cga);
}

static void t1000_write(uint32_t addr, uint8_t val, void *p) {
        t1000_t *t1000 = (t1000_t *)p;
        egawrites++;

        //        pclog("CGA_WRITE %04X %02X\n", addr, val);
        t1000->vram[addr & 0x3fff] = val;
        cycles -= 4;
}

static uint8_t t1000_read(uint32_t addr, void *p) {
        t1000_t *t1000 = (t1000_t *)p;
        egareads++;
        cycles -= 4;

        //        pclog("CGA_READ %04X\n", addr);
        return t1000->vram[addr & 0x3fff];
}

static void t1000_recalctimings(t1000_t *t1000) {
        double disptime;
        double _dispontime, _dispofftime;

        if (!t1000->internal) {
                cga_recalctimings(&t1000->cga);
                return;
        }
        disptime = 651;
        _dispontime = 640;
        _dispofftime = disptime - _dispontime;
        t1000->dispontime = (uint64_t)(_dispontime * (cpuclock / VID_CLOCK) * (double)(1ull << 32));
        t1000->dispofftime = (uint64_t)(_dispofftime * (cpuclock / VID_CLOCK) * (double)(1ull << 32));
}

/* Draw a row of text in 80-column mode */
static void t1000_text_row80(t1000_t *t1000) {
        uint32_t cols[2];
        int x, c;
        uint8_t chr, attr;
        int drawcursor;
        int cursorline;
        int bold;
        int blink;
        uint16_t addr;
        uint8_t sc;
        uint16_t ma = (t1000->cga.crtc[13] | (t1000->cga.crtc[12] << 8)) & 0x3fff;
        uint16_t ca = (t1000->cga.crtc[15] | (t1000->cga.crtc[14] << 8)) & 0x3fff;

        sc = (t1000->displine) & 7;
        addr = ((ma & ~1) + (t1000->displine >> 3) * 80) * 2;
        ma += (t1000->displine >> 3) * 80;

        if ((t1000->cga.crtc[10] & 0x60) == 0x20) {
                cursorline = 0;
        } else {
                cursorline = ((t1000->cga.crtc[10] & 0x0F) <= sc) && ((t1000->cga.crtc[11] & 0x0F) >= sc);
        }
        for (x = 0; x < 80; x++) {
                chr = t1000->vram[(addr + 2 * x) & 0x3FFF];
                attr = t1000->vram[(addr + 2 * x + 1) & 0x3FFF];
                drawcursor = ((ma == ca) && cursorline && (t1000->cga.cgamode & 8) && (t1000->cga.cgablink & 16));

                blink = ((t1000->cga.cgablink & 16) && (t1000->cga.cgamode & 0x20) && (attr & 0x80) && !drawcursor);

                if (t1000->video_options & 1)
                        bold = boldcols[attr] ? chr : chr + 256;
                else
                        bold = boldcols[attr] ? chr + 256 : chr;
                if (t1000->video_options & 2)
                        bold += 512;

                if (t1000->cga.cgamode & 0x20) /* Blink */
                {
                        cols[1] = blinkcols[attr][1];
                        cols[0] = blinkcols[attr][0];
                        if (blink)
                                cols[1] = cols[0];
                } else {
                        cols[1] = normcols[attr][1];
                        cols[0] = normcols[attr][0];
                }
                if (drawcursor) {
                        for (c = 0; c < 8; c++) {
                                ((uint32_t *)buffer32->line[t1000->displine])[(x << 3) + c] =
                                        cols[(fontdat[bold][sc] & (1 << (c ^ 7))) ? 1 : 0] ^ (blue ^ grey);
                        }
                } else {
                        for (c = 0; c < 8; c++)
                                ((uint32_t *)buffer32->line[t1000->displine])[(x << 3) + c] =
                                        cols[(fontdat[bold][sc] & (1 << (c ^ 7))) ? 1 : 0];
                }
                ++ma;
        }
}

/* Draw a row of text in 40-column mode */
static void t1000_text_row40(t1000_t *t1000) {
        uint32_t cols[2];
        int x, c;
        uint8_t chr, attr;
        int drawcursor;
        int cursorline;
        int bold;
        int blink;
        uint16_t addr;
        uint8_t sc;
        uint16_t ma = (t1000->cga.crtc[13] | (t1000->cga.crtc[12] << 8)) & 0x3fff;
        uint16_t ca = (t1000->cga.crtc[15] | (t1000->cga.crtc[14] << 8)) & 0x3fff;

        sc = (t1000->displine) & 7;
        addr = ((ma & ~1) + (t1000->displine >> 3) * 40) * 2;
        ma += (t1000->displine >> 3) * 40;

        if ((t1000->cga.crtc[10] & 0x60) == 0x20) {
                cursorline = 0;
        } else {
                cursorline = ((t1000->cga.crtc[10] & 0x0F) <= sc) && ((t1000->cga.crtc[11] & 0x0F) >= sc);
        }
        for (x = 0; x < 40; x++) {
                chr = t1000->vram[(addr + 2 * x) & 0x3FFF];
                attr = t1000->vram[(addr + 2 * x + 1) & 0x3FFF];
                drawcursor = ((ma == ca) && cursorline && (t1000->cga.cgamode & 8) && (t1000->cga.cgablink & 16));

                blink = ((t1000->cga.cgablink & 16) && (t1000->cga.cgamode & 0x20) && (attr & 0x80) && !drawcursor);

                if (t1000->video_options & 1)
                        bold = boldcols[attr] ? chr : chr + 256;
                else
                        bold = boldcols[attr] ? chr + 256 : chr;
                if (t1000->video_options & 2)
                        bold += 512;

                if (t1000->cga.cgamode & 0x20) /* Blink */
                {
                        cols[1] = blinkcols[attr][1];
                        cols[0] = blinkcols[attr][0];
                        if (blink)
                                cols[1] = cols[0];
                } else {
                        cols[1] = normcols[attr][1];
                        cols[0] = normcols[attr][0];
                }
                if (drawcursor) {
                        for (c = 0; c < 8; c++) {
                                ((uint32_t *)buffer32->line[t1000->displine])[(x << 4) + c * 2] =
                                        ((uint32_t *)buffer32->line[t1000->displine])[(x << 4) + c * 2 + 1] =
                                                cols[(fontdat[bold][sc] & (1 << (c ^ 7))) ? 1 : 0] ^ (blue ^ grey);
                        }
                } else {
                        for (c = 0; c < 8; c++) {
                                ((uint32_t *)buffer32->line[t1000->displine])[(x << 4) + c * 2] =
                                        ((uint32_t *)buffer32->line[t1000->displine])[(x << 4) + c * 2 + 1] =
                                                cols[(fontdat[bold][sc] & (1 << (c ^ 7))) ? 1 : 0];
                        }
                }
                ++ma;
        }
}

/* Draw a line in CGA 640x200 mode */
static void t1000_cgaline6(t1000_t *t1000) {
        int x, c;
        uint8_t dat;
        uint32_t ink = 0;
        uint16_t addr;
        uint32_t fg = (t1000->cga.cgacol & 0x0F) ? blue : grey;
        uint32_t bg = grey;

        uint16_t ma = (t1000->cga.crtc[13] | (t1000->cga.crtc[12] << 8)) & 0x3fff;

        addr = ((t1000->displine) & 1) * 0x2000 + (t1000->displine >> 1) * 80 + ((ma & ~1) << 1);

        for (x = 0; x < 80; x++) {
                dat = t1000->vram[addr & 0x3FFF];
                addr++;

                for (c = 0; c < 8; c++) {
                        ink = (dat & 0x80) ? fg : bg;
                        if (!(t1000->cga.cgamode & 8))
                                ink = grey;
                        ((uint32_t *)buffer32->line[t1000->displine])[x * 8 + c] = ink;
                        dat = dat << 1;
                }
        }
}

/* Draw a line in CGA 320x200 mode. Here the CGA colours are converted to
 * dither patterns: colour 1 to 25% grey, colour 2 to 50% grey */
static void t1000_cgaline4(t1000_t *t1000) {
        int x, c;
        uint8_t dat, pattern;
        uint32_t ink0, ink1;
        uint16_t addr;

        uint16_t ma = (t1000->cga.crtc[13] | (t1000->cga.crtc[12] << 8)) & 0x3fff;
        addr = ((t1000->displine) & 1) * 0x2000 + (t1000->displine >> 1) * 80 + ((ma & ~1) << 1);

        for (x = 0; x < 80; x++) {
                dat = t1000->vram[addr & 0x3FFF];
                addr++;

                for (c = 0; c < 4; c++) {
                        pattern = (dat & 0xC0) >> 6;
                        if (!(t1000->cga.cgamode & 8))
                                pattern = 0;

                        switch (pattern & 3) {
                        case 0:
                                ink0 = ink1 = grey;
                                break;
                        case 1:
                                if (t1000->displine & 1) {
                                        ink0 = grey;
                                        ink1 = grey;
                                } else {
                                        ink0 = blue;
                                        ink1 = grey;
                                }
                                break;
                        case 2:
                                if (t1000->displine & 1) {
                                        ink0 = grey;
                                        ink1 = blue;
                                } else {
                                        ink0 = blue;
                                        ink1 = grey;
                                }
                                break;
                        case 3:
                                ink0 = ink1 = blue;
                                break;
                        }
                        ((uint32_t *)buffer32->line[t1000->displine])[x * 8 + 2 * c] = ink0;
                        ((uint32_t *)buffer32->line[t1000->displine])[x * 8 + 2 * c + 1] = ink1;
                        dat = dat << 2;
                }
        }
}

static void t1000_poll(void *p) {
        t1000_t *t1000 = (t1000_t *)p;

        if (t1000->video_options != st_video_options || t1000->enabled != st_enabled) {
                t1000->video_options = st_video_options;
                t1000->enabled = st_enabled;

                /* Set the font used for the external display */
                t1000->cga.fontbase = ((t1000->video_options & 3) * 256);

                if (t1000->enabled) /* Disable internal chipset */
                        mem_mapping_enable(&t1000->mapping);
                else
                        mem_mapping_disable(&t1000->mapping);
        }
        /* Switch between internal plasma and external CRT display. */
        if (st_display_internal != T1000_OUTPUT_DISPLAY_UNSET && st_display_internal != t1000->internal) {
                t1000->internal = st_display_internal;
                t1000_recalctimings(t1000);
        }
        if (!t1000->internal) {
                cga_poll(&t1000->cga);
                return;
        }

        if (!t1000->linepos) {
                timer_advance_u64(&t1000->cga.timer, t1000->dispofftime);
                t1000->cga.cgastat |= 1;
                t1000->linepos = 1;
                if (t1000->dispon) {
                        if (t1000->displine == 0) {
                                video_wait_for_buffer();
                        }

                        /* Graphics */
                        if (t1000->cga.cgamode & 0x02) {
                                if (t1000->cga.cgamode & 0x10)
                                        t1000_cgaline6(t1000);
                                else
                                        t1000_cgaline4(t1000);
                        } else if (t1000->cga.cgamode & 0x01) /* High-res text */
                        {
                                t1000_text_row80(t1000);
                        } else {
                                t1000_text_row40(t1000);
                        }
                }
                t1000->displine++;
                /* Hardcode a fixed refresh rate and VSYNC timing */
                if (t1000->displine == 200) /* Start of VSYNC */
                {
                        t1000->cga.cgastat |= 8;
                        t1000->dispon = 0;
                }
                if (t1000->displine == 216) /* End of VSYNC */
                {
                        t1000->displine = 0;
                        t1000->cga.cgastat &= ~8;
                        t1000->dispon = 1;
                }
        } else {
                if (t1000->dispon) {
                        t1000->cga.cgastat &= ~1;
                }
                timer_advance_u64(&t1000->cga.timer, t1000->dispontime);
                t1000->linepos = 0;

                if (t1000->displine == 200) {
                        /* Hardcode 640x200 window size */
                        if (T1000_XSIZE != xsize || T1000_YSIZE != ysize) {
                                xsize = T1000_XSIZE;
                                ysize = T1000_YSIZE;
                                if (xsize < 64)
                                        xsize = 656;
                                if (ysize < 32)
                                        ysize = 200;
                                updatewindowsize(xsize, ysize);
                        }
                        video_blit_memtoscreen(0, 0, 0, ysize, xsize, ysize);

                        frames++;
                        /* Fixed 640x200 resolution */
                        video_res_x = T1000_XSIZE;
                        video_res_y = T1000_YSIZE;

                        if (t1000->cga.cgamode & 0x02) {
                                if (t1000->cga.cgamode & 0x10)
                                        video_bpp = 1;
                                else
                                        video_bpp = 2;

                        } else
                                video_bpp = 0;
                        t1000->cga.cgablink++;
                }
        }
}

static void t1000_recalcattrs(t1000_t *t1000) {
        int n;

        /* val behaves as follows:
         *     Bit 0: Attributes 01-06, 08-0E are inverse video
         *     Bit 1: Attributes 01-06, 08-0E are bold
         *     Bit 2: Attributes 11-16, 18-1F, 21-26, 28-2F ... F1-F6, F8-FF
         * 	      are inverse video
         *     Bit 3: Attributes 11-16, 18-1F, 21-26, 28-2F ... F1-F6, F8-FF
         * 	      are bold */

        /* Set up colours */
        blue = makecol(0x2D, 0x39, 0x5A);
        grey = makecol(0x85, 0xa0, 0xD6);

        /* Initialise the attribute mapping. Start by defaulting everything
         * to grey on blue, and with bold set by bit 3 */
        for (n = 0; n < 256; n++) {
                boldcols[n] = (n & 8) != 0;
                blinkcols[n][0] = normcols[n][0] = blue;
                blinkcols[n][1] = normcols[n][1] = grey;
        }

        /* Colours 0x11-0xFF are controlled by bits 2 and 3 of the
         * passed value. Exclude x0 and x8, which are always grey on
         * blue. */
        for (n = 0x11; n <= 0xFF; n++) {
                if ((n & 7) == 0)
                        continue;
                if (t1000->attrmap & 4) /* Inverse */
                {
                        blinkcols[n][0] = normcols[n][0] = blue;
                        blinkcols[n][1] = normcols[n][1] = grey;
                } else /* Normal */
                {
                        blinkcols[n][0] = normcols[n][0] = grey;
                        blinkcols[n][1] = normcols[n][1] = blue;
                }
                if (t1000->attrmap & 8)
                        boldcols[n] = 1; /* Bold */
        }
        /* Set up the 01-0E range, controlled by bits 0 and 1 of the
         * passed value. When blinking is enabled this also affects 81-8E. */
        for (n = 0x01; n <= 0x0E; n++) {
                if (n == 7)
                        continue;
                if (t1000->attrmap & 1) {
                        blinkcols[n][0] = normcols[n][0] = blue;
                        blinkcols[n][1] = normcols[n][1] = grey;
                        blinkcols[n + 128][0] = blue;
                        blinkcols[n + 128][1] = grey;
                } else {
                        blinkcols[n][0] = normcols[n][0] = grey;
                        blinkcols[n][1] = normcols[n][1] = blue;
                        blinkcols[n + 128][0] = grey;
                        blinkcols[n + 128][1] = blue;
                }
                if (t1000->attrmap & 2)
                        boldcols[n] = 1;
        }
        /* Colours 07 and 0F are always blue on grey. If blinking is
         * enabled so are 87 and 8F. */
        for (n = 0x07; n <= 0x0F; n += 8) {
                blinkcols[n][0] = normcols[n][0] = grey;
                blinkcols[n][1] = normcols[n][1] = blue;
                blinkcols[n + 128][0] = grey;
                blinkcols[n + 128][1] = blue;
        }
        /* When not blinking, colours 81-8F are always blue on grey. */
        for (n = 0x81; n <= 0x8F; n++) {
                normcols[n][0] = grey;
                normcols[n][1] = blue;
                boldcols[n] = (n & 0x08) != 0;
        }

        /* Finally do the ones which are solid grey. These differ between
         * the normal and blinking mappings */
        for (n = 0; n <= 0xFF; n += 0x11) {
                normcols[n][0] = normcols[n][1] = grey;
        }
        /* In the blinking range, 00 11 22 .. 77 and 80 91 A2 .. F7 are grey */
        for (n = 0; n <= 0x77; n += 0x11) {
                blinkcols[n][0] = blinkcols[n][1] = grey;
                blinkcols[n + 128][0] = blinkcols[n + 128][1] = grey;
        }
}

static void *t1000_init() {
        t1000_t *t1000 = malloc(sizeof(t1000_t));
        memset(t1000, 0, sizeof(t1000_t));
        cga_init(&t1000->cga);

        t1000->internal = 1;

        /* 16k video RAM */
        t1000->vram = malloc(0x4000);

        timer_set_callback(&t1000->cga.timer, t1000_poll);
        timer_set_p(&t1000->cga.timer, t1000);

        /* Occupy memory between 0xB8000 and 0xBFFFF */
        mem_mapping_add(&t1000->mapping, 0xb8000, 0x8000, t1000_read, NULL, NULL, t1000_write, NULL, NULL, NULL, 0, t1000);
        /* Respond to CGA I/O ports */
        io_sethandler(0x03d0, 0x000c, t1000_in, NULL, NULL, t1000_out, NULL, NULL, t1000);

        /* Default attribute mapping is 4 */
        t1000->attrmap = 4;
        t1000_recalcattrs(t1000);

        /* Start off in 80x25 text mode */
        t1000->cga.cgastat = 0xF4;
        t1000->cga.vram = t1000->vram;
        t1000->enabled = 1;
        t1000->video_options = 0x01;
        language = device_get_config_int("display_language") ? 2 : 0;
        return t1000;
}

static void t1000_close(void *p) {
        t1000_t *t1000 = (t1000_t *)p;

        free(t1000->vram);
        free(t1000);
}

static void t1000_speed_changed(void *p) {
        t1000_t *t1000 = (t1000_t *)p;

        t1000_recalctimings(t1000);
}

static device_config_t t1000_config[] = {
        {.name = "display_language",
         .description = "Language",
         .type = CONFIG_SELECTION,
         .selection = {{.description = "USA", .value = 0}, {.description = "Danish", .value = 1}},
         .default_int = 0},
        {.type = -1}};

device_t t1000_device = {"Toshiba T1000", 0, t1000_init, t1000_close, NULL, t1000_speed_changed, NULL, NULL, t1000_config};
